Designing Disaster Recovery Clusters using Metroclusters and Continentalclusters, Reprinted October 2011 (5900-1881)

Symmetrix CLI database on each node has already been setup, as described in the section,
“Preparing the Cluster for Data Replication” (page 257).
CAUTION: M by N configurations cannot be used with R1/R2 swapping.
Figure 47 depicts a 2 by 2 configuration. Data in this figure are used in the example commands
given in the following sections. This example shows R1 devices at one data center and R2 devices
with Business Continuity Volumes (BCVs) at the other. However, a bidirectional configuration is
also possible, with R1 devices on both sites.
Figure 47 Devices and Symmetrix Units in M by N Configurations
Creating Symmetrix Device Groups
For each node on the R1 side (node1 and node2), create the device groups as follows. Note: It
is necessary to create two device groups since device groups do not span frames.
The following examples are based on the configuration shown in Figure 47.
1. Create device groups using the following commands on each node on the R1 side.
# symdg -type RDF1 create dgoraA
# symdg -type RDF1 create dgoraB
2. For each node on the R2 side (node3 and node4), create the device groups as follows. Note:
It is necessary to create two device groups since device groups do not span frames. Do the
following on each node on the R2 side.
# symdg -type RDF2 create dgoraA
# symdg -type RDF2 create dgoraB
3. For each node on the R1 side (node1 and node2), assign the R1 devices to the device groups.
# symld -sid 638 -g dgoraA add dev 00C
# symld -sid 638 -g dgoraA add dev 00D
# symld -sid 130 -g dgoraB add dev 010
# symld -sid 130 -g dgoraB add dev 011
4. For each node on the R2 side (node3 and node4), assign the R2 devices to the device groups.
# symld -sid 021 -g dgoraA add dev 018
# symld -sid 021 -g dgoraA add dev 019
# symld -sid 363 -g dgoraB add dev 050
# symld -sid 363 -g dgoraB add dev 051
266 Building Disaster Recovery Serviceguard Solutions Using Metrocluster with EMC SRDF